What would you do?.....

This has really been bugging me. So my bf and his friend always hung out, doing podcasts and going to happy hour together. Apparently one night that they were out, there was a female friend with them. This female friend accused my bf's friend of drugging and raping her. He denied to my bf anything sexual happened with her, yet the detective later told my bf that the his friend admitted to them sleeping together, but said it was consensual. This happened while he was engaged, he's now married. Nothing happened with the police investigation and the girl moved hours away. The male friend cut off contact with my bf and their other friends, but not before he continuously called and harrassed the wife of his other friend, which he was the best man of their wedding. My issue is everyone knows all this fucked up shit about this guy and his wife is oblivious. I want to tell her....